This invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to developer, toner plus carrier, and toner compositions containing novel amic acid based resins, and process for the preparation thereof. In embodiments, there are provided in accordance with the present invention, deinkable toner compositions comprised of polyamic acid resin or polyester amic acid resin obtained, for example, by solution or melt condensation processes, and pigment particles comprised of, for example, carbon black, magnetites, or mixtures thereof, cyan, magenta, yellow, blue, green, red, or brown components, or mixtures thereof, thereby providing for the development and generation of black and/or colored images. In embodiments, there are provided in accordance with the present invention polyamic acid resins, or mixtures thereof, and which resins are illustrated with reference to the following formula ##STR1## wherein R is a tetrasubstituted aromatic or aliphatic moiety with 5 and preferably 6 to 36 carbon atoms; R' is alkylene, alkyleneoxyalkylene or a poly(alkyleneoxy)alkylene group; and n represents the number of segments and is preferably a number of from about 1 to about 500; or polyester amic acid of the following formula ##STR2## wherein X is a tetrasubstituted aromatic or cycloaliphatic group with 5 to 36 carbon atoms; R is alkylene, alkyleneoxyalkylene or poly(alkyleneoxy)alkylene; and R' is a divalent aromatic with 6 to 36 carbon atoms or aliphatic group with 2 to 20 carbon atoms; and n and m represent, respectively, the number of random segments of the polymer and are from about 10 to about 500.
The polyamic acid resin or polyester amic acid resin of this invention can also be represented in the zwitterionic form, that is a structure wherein the charges of the carboxylic and amide moeities are neutralized and represented by the formulas ##STR3## wherein X is a tetrasubstituted aromatic or cycloaliphatic group with 6 to 36 carbon atoms; R is alkylene, alkyleneoxyalkylene or poly(alkyleneoxy)alkylene; and R' is a divalent aromatic with 6 to 36 carbon atoms or aliphatic group with 2 to 20 carbon atoms; and wherein n and m respectively, represent repeating segments and can be a number of from about 10 to about 500.
In the aforementioned polyamic acid or polyester amic acid structures, the X group is a tetrasubstituted aromatic or tetrasubstituted aliphatic radical of from about 5 to 36 carbon atoms. Examples of the tetrasubstituted aromatic group, X, include radicals of cyclopentadiene, benzene, anthracene, biphenylene, diphenylene, phenanthracene, perylene, diphenyloxide, diphenylsulfoxide, diphenyl-hexafluoropropane, diphenylsulfone, benzophenone and the like, such as illustrated by the formulas ##STR4## wherein the dotted lines represent covalent bonds from the radical moiety (X) to the carbonyl groups of the aforementioned amic acid resin structures.
Examples of the tetrasubstituted aliphatic groups, X, include radicals of cyclohexane, cyclopentane, 3-methyl-3-cyclohexene, bicyclo[2,2,2]octane, 4-methyl-3-cyclohexene, 1,1', 2,2'-tetramethylene ethylenediamine, mixture thereof and the like, as illustrated by the formula ##STR5## wherein the dotted lines represent covalent bonds from the radical moiety (X) to the carbonyl groups of the aforementioned amic acid resin structures. The R groups of the aforementioned amic acid based resin, include alkylene moieties of from about 2 to 25 carbon atoms such as ethylene, 1,2-propylene, 1,3-propylene, 1,3-butylene, 1,4-butylene, pentylene, hexylene, decylene, alkyleneoxyalkylene such as ethyleneoxyethylene, propyleneoxypropylene, butyleneoxybutylene, ethyleneoxyethylene oxyethylene, ethyleneoxyethyleneoxyethylene oxyethylene, propyleneoxypropylene oxypropylene, poly(alkyleneoxy)-alkylene, mixtures thereof and the like. Examples of R' of the polyester amic acid resins include disubstituted aromatic or aliphatic groups such as the divalent phenylene, anthrylene, cyclohexylene, ethylene, propylene, butylene, pentylene, naphthalylene, biphenylene, 2-methylpentylene, hexylene, octylene decylene groups, mixtures thereof and the like.
The toner compositions of the present invention in embodiments possess a number of advantages including excellent deinkability, possess low fixing characteristics such as from about 120.degree. C. to about 145.degree. C., excellent blocking characteristics such as from about 45.degree. C. to about 65.degree. C., excellent nonvinyl-offset properties, and low relative humidity sensitivities.
The polyamic acid based resins of the present invention can in embodiments be generated by the reaction of a dianhydride such as pyromellitic dianhydride, benzophenone dianhydride, 5-(2,5-dioxotetrahydrol)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (I) or 5-(2,5-dioxotetrahydrol)-4-methyl-3-cyclohexene- 1,2odicarboxylic anhydride (II) available as B-4400 and B-5060, respectively, from Dai Nippon Ink Company, ##STR6## and a diamino-terminated oxyalkyl or polyoxy alkyl, such as JEFFAMINES.TM. available from Texaco Chemicals as JEFFAMINE D-230.TM., D-400.TM., D-700.TM., EDR-148.TM., EDR-192.TM. and believed to be of the following formula, or aliphatic diamines like DYTEK.TM.. ##STR7##
The aforementioned amic acid based resins exhibit in embodiments a number average molecular weight of from about 2,500 grams per mole to about 100,000 grams per mole, as measured by vapor phase osmometer, have a glass transition temperature of from about 45.degree. C. to about 65.degree. C., and more preferably of from about 50.degree. C. to about 65.degree. C. as measured by the Differential Scanning Calorimeter, low fixing characteristics, such as from about 125.degree. C. to about 145.degree. C., and excellent deinkability.
In embodiments, the polyamic acid resin of the present invention can be branched or crosslinked by utilizing an alkyltriamine or oxyalkyltriamine, such as JEFFAMINE T-403.TM. available from Texaco Company, and believed to be of the formula ##STR8## wherein the sum of x, y and z is, for example, about 5.3. The amount of branching monomer utilized is from about 0.5 to about 6 percent by weight of polyamic acid.
The polyamic acid based resins of the present invention can in embodiments be generated by the reaction of an ester dianhydride such as ethylene glycol bis-(anhydro-trimellitate), alkylene glycol bis-(anhydrotrimellitate), or glycerol bis-(anhydro-trimellitate) available as AC-32 from Anhydride Chemical Company, and represented by the formula ##STR9## wherein R is acetyl, trimellitate anhydro and a diamino-terminated oxyalkyl or polyoxy alkyl, such as the aforementioned JEFFAMINES.TM. available from Texaco Chemicals.
A number of toner resins are known, such as styrene acrylates, styrene methacrylates, styrene butadienes, polyesters, polyamides, polyimides generally, polyester imides and the like.
Deinkable toner resins are disclosed in U.S. Pat. No. 5,409,793 the disclosure of which is totally incorporated herein by reference, which illustrates a toner comprised of pigment, and a polyimide-imine resin of the formula ##STR10## wherein m and n represent the number of monomer segments; X is independently selected from the group consisting of a tetravalent aromatic, polyarylomatic or cycloaliphatic group with from about 6 to about 20 carbon atoms and a cycloaliphatic group; R is independently selected from the group consisting of alkylene, oxyalkylene and polyoxyalkylene; and R' is independently selected from the group consisting of alkyl, alkylene and arylene. The toners of the aforementioned U. S. Pat. No. 5,409,793 can be considered deinkable in embodiments in caustic aqueous conditions of from about pH of 10 to about a pH of 14, and wherein the toner resin is believed to be decomposed to oligomers. This differs from the present invention in embodiments with regard to deinkability in that, for example, the invention polyamic acid can be deinked from paper at milder caustic conditions, such as from about pH of 8 to about a pH of 10 without surfactants, and wherein the toner resin is believed to be dissolved and not decomposed. The soluble polyamic acid resin can then be reclaimed from the process by adjusting the pH of the media below pH of 7, and more specifically from about 3 to about 6.8. The lower pH conditions for deinking also allows for less caustic reagents to be utilized.
Additionally, other deinkable polyimide or polyester imide toner resin are disclosed in U. S. Pat. No. 5,427,882, 5,413,889, 5,411,829, 5,427,881, and U.S. Pat. Nos. 5,348,830 and 5,348,831, the disclosures of each being totally incorporated herein by reference. Similarly, these deinkable toners differ in that, for example, caustic aqueous conditions of from about pH of 10 to about a pH of 14 is necessary, whereas with the amic acid based toner resin of this invention requires less caustic reagents such that a pH of from about 8 to 10 is necessary. Some specifics of the deinking process are disclosed in copending application U.S. Ser. No. 394,990, the disclosure of which is totally incorporated herein by reference. Moreover, in copending application U.S. Ser. No. 394,974, the disclosure of which is totally incorporated herein by reference, there is illustrated a toner composition comprised of a pigment and a polyimideamic acid resin.
The disclosures of each of the above mentioned copending applications and the patents that result therefrom are totally incorporated herein by reference.